An electromagnetic clutch having a thermal fuse is disclosed in Patent Literature 1. The thermal fuse is melted and disconnected by frictional heat generated between a friction surface of an armature and a friction surface of a rotor at the time of occurrence of locking of a compressor to cut supply of an electric current to an electromagnetic coil and thereby to place the electromagnetic clutch in a drive force blocked state.
In the electromagnetic clutch of Patent Literature 1, the thermal fuse is placed in an inside of a stator and is covered with a resin member that seals an opening of the stator. The thermal fuse is fixed in the inside of the stator by the resin member.
In the above prior art technique, similar to a comparative example discussed later, a surface of the resin member, which covers the thermal fuse, is a planar surface that is perpendicular to a rotational center axis of the rotor. Therefore, the resin member, which covers the thermal fuse, is thin in an axial direction of the rotational center axis of the rotor but is thick in an oblique direction, which is oblique to the rotational center axis. Therefore, radiant heat, which is incident to the resin member in the oblique direction being oblique to the rotational center axis and is directed to a center of the thermal fuse in the oblique direction, is not easily conducted to the thermal fuse. Because of the above described reason, the response of the thermal fuse is low in the above-described prior art technique.